From momentous events like a baby's first steps to the seriously mundane -- "I think I need to hit up the self-help section of Barnes and Nobles. ... Like soon" -- Facebook is the way we share our lives.
"In a world without it, I think I would die," said Giulia Easthope, 15. She spends at least four to five hours a day on Facebook and has 466 friends.
"I love Facebook because it's one of the easiest ways to keep up with the people in your life and you can, like, talk to them and you can send them videos or pictures," Easthope said.
Facebook is, in the simplest terms, an engine of human connection. Give Facebook a few vital facts about yourself and it gives you a direct line to your past, present and future, changing lives.
Since then, it's mushroomed from a favorite of college students to a favorite of grandparents too. In the last 15 months, Facebook has added around eight new users every second.
Having reached 500 million users, the six-year-old startup is one of the fastest growing companies in recent years.
Facebook essentially has replaced the mall, where for years teens have gone to gather, gossip and get away.
Its profile pages are the modern-day equivalent of paging through someone's record collection for clues about who they are.
"I love music," said Anthony Dean, 14. He has 329 friends and plays bass in a band. He said he usually spent one or two hours a day on Facebook.
"People always post their favorite kinds of music," he said, "and if they post bad music, I think less of them."
Facebook has singlehandedly redefined what a friend is.
"I've been able to reconnect with some people I haven't seen for 28, 30 years," said mother of three Dawn Waugh. She has 19 Facebook friends.
It also has been the bearer of somber news.
"My sister-in-law lost her battle with leukemia this morning. She was 45," read Dana Nicolette's Facebook status on June 8 at 4:47 p.m.
"I think the only reason I shared that on Facebook was that it's just too hard to call everyone," said Nicolette, 34, with 535 friends. "[Facebook's] almost like journaling. It helps you cope."
Private moments are shared -- big like the arrival of a new baby and small like a set of new braces. The moments can boost the morale of those far away from home. And it hasn't just helped connect families; it's helped build them.
Molly and John Connolly, who have 492 friends, created a Facebook group in hopes of finding a birthmother.
Their group posting read: "Dear friends, John and I are trying to adopt a baby. We are asking for your help in passing along our Web information to those on your friend list. You never know who may be able to put us in touch with a birthmother. Here's our profile link."
"That's how we connected [with the birthmother.] We started talking to her, and before we knew it -- it happened really fast -- we had our wonderful baby boy Theadore," Molly Connolly said.
For others, Facebook provided a chance to get in touch with a lost love. Sometimes, the results have been nothing short of cinematic.
Five years ago, Don Granade became a widower. After he moved closer to his children, he asked his daughter Ginger to look up his first love, Marvella. Ginger found her on Facebook and now she and Granade are married.